System and Method for Supplying a Precursor for an Atomic Layer Deposition (ALD) Process

ABSTRACT

Systems and methods for supplying a precursor material for an atomic layer deposition (ALD) process are provided. A gas supply provides one or more precursor materials to a deposition chamber. The deposition chamber receives the one or more precursor materials via an input line. A gas circulation system is coupled to an output line of the deposition chamber. The gas circulation system includes a gas composition detection system configured to produce an output signal indicating a composition of a gas exiting the deposition chamber through the output line. The gas circulation system also includes a circulation line configured to transport the gas exiting the deposition chamber to the input line. A controller is coupled to the gas supply. The controller controls the providing of the one or more precursor materials by the gas supply based on the output signal of the gas composition detection system.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application under 35 U.S.C. § 121 ofU.S. patent application Ser. No. 14/071,784, filed on Nov. 5, 2013, thecontents of which are incorporated herein by reference in its entirety.

TECHNICAL FIELD

The technology described in this disclosure relates generally to anatomic layer deposition (ALD) process and more particularly to systemsand methods for reducing an amount of precursor material used in an ALDprocess.

BACKGROUND

Semiconductor processing in the fabrication of integrated circuitry mayinvolve the deposition of layers on semiconductor substrates. Exemplaryprocesses for performing such depositions may include chemical vapordeposition (CVD) processes and atomic layer deposition (ALD) processes,among others. The CVD and ALD processes may be conducted within adeposition chamber that retains one or more substrates upon a waferholder. In an ALD process, one or more precursor gases may be providedto a showerhead within the deposition chamber, where the showerhead mayprovide the one or more precursor gases uniformly over an outer surfaceof the substrate. The one or more precursor gases may react or otherwisecause a layer to be deposited substantially over the substrate. Plasmaenhancement may or may not be utilized in the ALD process. If plasmaenhancement is utilized, a plasma may be generated and maintained eitherwithin the chamber or remote from the chamber.

SUMMARY

The present disclosure is directed to systems and methods for supplyinga precursor material for an atomic layer deposition (ALD) process. Asystem for supplying a precursor material for an ALD process includes agas supply for providing one or more precursor materials to a depositionchamber. The deposition chamber receives the one or more precursormaterials via an input line of the deposition chamber. The system alsoincludes a gas circulation system coupled to an output line of thedeposition chamber. The gas circulation system includes a gascomposition detection system configured to produce an output signalindicating a composition of a gas exiting the deposition chamber throughthe output line. The gas circulation system also includes a circulationline configured to transport the gas exiting the deposition chamber tothe input line. The circulation line causes the gas exiting thedeposition chamber to be transported back into the deposition chamber.The system further includes a controller coupled to the gas supply. Thecontroller controls the providing of the one or more precursor materialsby the gas supply based on the output signal of the gas compositiondetection system.

In another example, a system for supplying a precursor material for anALD process includes a gas supply for providing one or more precursormaterials to a deposition chamber. The system also includes a gascirculation system coupled to an output line of the deposition chamber.The gas circulation system is configured to transport gas exiting thedeposition chamber to an input line of the deposition chamber, where thegas circulation system causes the gas exiting the deposition chamber tobe transported back into the deposition chamber. The system alsoincludes a filter coupled to the gas circulation system, where thefilter reduces contaminants in the gas being transported back into thedeposition chamber. The system further includes a gas compositiondetection system coupled to the output line. The gas compositiondetection system is configured to produce an output signal indicating acomposition of the gas exiting the deposition chamber. A purge gasdelivery system is configured to deliver a purge gas to the depositionchamber via a plurality of purge lines. The system also includes acontroller coupled to the gas supply, where the controller controls theproviding of the one or more precursor materials to the depositionchamber.

In another example, in a method for supplying a precursor material foran ALD process, one or more precursor materials are provided to adeposition chamber. A composition of a gas exiting the depositionchamber is monitored. The gas exiting the deposition chamber istransported back into the deposition chamber via a circulation system.The providing of the one or more precursor materials and thetransporting of the gas back into the deposition chamber are controlledbased on the monitored composition of the gas exiting the depositionchamber.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts an example system for supplying a precursor material foran atomic layer deposition (ALD) process.

FIG. 2 depicts an example system for supplying a precursor material to adeposition chamber for an ALD process, where the example system mayinclude a gas circulation system for causing gas exiting the depositionchamber to be transported back into the deposition chamber.

FIG. 3 depicts an example deposition system that may be used to form adeposited layer on a substrate or other structure.

FIG. 4 is a flowchart illustrating an example method for supplying aprecursor material for an ALD process.

DETAILED DESCRIPTION

FIG. 1 depicts an example system 100 for supplying a precursor materialfor an atomic layer deposition (ALD) process. The example system 100 ofFIG. 1 may include a gas supply 102 for supplying one or more precursormaterials to a deposition chamber 104. In one example, the gas supply102 may include a plurality of gas canisters, where the plurality of gascanisters may be used to supply different precursor materials used inthe ALD process. The gas supply 102 may supply the one or more precursormaterials to the deposition chamber 104 via an input line 106 of thedeposition chamber. Although the input line 106 in the example of FIG. 1is depicted as being open-ended, such that the input line 106 may beconnected to various other external systems (e.g., pump systems, othergas supply systems, etc.), in other examples, the input line 106 may beconnected directly to the gas supply 102, such that other externalsystems may not be connected to the input line 106. The gas supply 102may supply the one or more precursor materials to the input line 106 viaa supply line 103 that couples the input line 106 to the gas supply 102.

As described in further detail below with reference to FIG. 3, thedeposition chamber 104 may include a mounting platform or other hardwareon which a substrate may be placed. The example system 100 of FIG. 1 maybe used to form one or more deposited layers on the substrate. Thedeposition chamber 104 may include an output line 110 that allows gasesand other matter to exit the deposition chamber 104. The output line 110may include, for example, an exhaust outlet that allows the gases andother matter to exit the deposition chamber 104. In some examples, avacuum pump may be connected to the output line 110 in order to helpevacuate the gases and other matter from the deposition chamber 104.Such a vacuum pump may also be utilized to reduce and control a pressurewithin the deposition chamber 104 to a desired pressure. The gases andother matter that exit the deposition chamber 104 may include the one ormore precursor materials introduced to the deposition chamber 104 viathe input line 106.

A gas circulation system 108 may be coupled to the output line 110 ofthe deposition chamber 104. The gas circulation system 108 may be usedto reduce an amount of the one or more precursor materials that are usedin the ALD process. For example, in conventional systems that do notutilize the gas circulation system 108, the one or more precursormaterials may be evacuated from the deposition chamber 104 via theoutput line 110 and directed to an exhaust system (e.g., a typicalexhaust system including a filtering system that is exhausted to theatmosphere). Such conventional systems may use a high amount of the oneor more precursor materials because a large amount of the precursormaterials may be discarded after exiting the deposition chamber 104. Bycontrast, the system 100 including the gas circulation system 108 may beused to lower precursor waste in ALD processes and thus also lowerproduction costs.

The gas circulation system 108 may lower precursor waste by providing acirculation line 116 that may be coupled between the gas circulationsystem 108 and the input line 106. The circulation line 116 may beconfigured to transport the gas exiting the deposition chamber 104 tothe input line 106, which may cause the gas exiting the depositionchamber 104 to be transported back into the deposition chamber 104. Inthis manner, by circulating precursor gases back into the depositionchamber, rather than directing them to an exhaust system to bediscarded, the gas circulation system 108 may reduce precursor waste inthe ALD system 100.

In addition to including the circulation line 116, the gas circulationsystem 108 coupled to the output line 110 of the deposition chamber 104may also include a gas composition detection system 112. The gascomposition detection system 112 may be configured to monitor the gasexiting the deposition chamber 104 and to produce an output signalindicating a composition of the gas. The gas composition detectionsystem 112 may include one or more different monitoring components,including, for example, a Fourier transform infrared spectroscopy (FTIR)system, a nondispersive infrared sensor (NDIR) system, or a Piezocon gasconcentration sensor (PZC) system. Various other types of gascomposition monitoring systems may be used in the gas compositiondetection system 112.

The gas circulation system 108, and specifically, the gas compositiondetection system 112 included therein, may be coupled to a controller118 via a connection 114 (e.g., electrical connection, opticalconnection, etc.). The controller 118 may also be coupled to the gassupply 102, as illustrated in the example of FIG. 1. The controller 118may control the providing of the one or more precursor materials by thegas supply 102 to the deposition chamber 104. Specifically, thecontroller 118 may control the providing of the one or more precursormaterials based on the output signal of the gas composition detectionsystem 112, where the output signal may be provided to the controller118 via the connection 114. Thus, for example, the controller 118 mayreceive the output signal of the gas composition detection system 112,where the output signal may indicate that a particular precursormaterial is not of an adequate amount in the gas exiting the depositionchamber 104. Based on this output signal, the controller 118 may controlthe gas supply 102 to cause more of the particular precursor material toenter the deposition chamber 104.

In this example, the gas composition detection system 112 may thusprovide a feedback signal to the controller 118, such that a compositionof the gas in the chamber 104 may be controlled. In other examples, thegas composition detection system 112 may not be connected to thecontroller 118, and in such examples, the controller 118 may be used tocontrol the providing of the precursor materials to the chamber 104without a feedback signal. In such systems where the gas compositiondetection system 112 is not connected to the controller 118, the gascomposition detection system 112 may be used for other purposes. Forexample, the gas composition detection system 112 may be used to monitorthe composition of the gas exiting the chamber 104 to determine if thegas should be transported back into the chamber 104 via the circulationline 116.

FIG. 2 depicts an example system 200 for supplying a precursor materialto a deposition chamber 204 for an ALD process, where the example system200 may include a gas circulation system 208 for causing gas exiting thedeposition chamber 204 to be transported back into the depositionchamber 204. The example system 200 of FIG. 2 may include componentssimilar to those included in the example system 100 of FIG. 1. Forexample, the example system 200 may include a gas supply 202 forsupplying one or more precursor materials to a deposition chamber 204via a supply line 203. The supply line 203 may be coupled to an inputline 206 of the deposition chamber 204, such that the one or moreprecursor materials enter the chamber 204 via the input line 206. Thedeposition chamber 204 may include suitable hardware for holding asubstrate and may also include an output line 210 that allows gases(e.g., the one or more precursor materials, purge gas, etc.) and othermatter to exit the deposition chamber 204.

A gas circulation system 208 may be coupled to the output line 210 ofthe deposition chamber 204, where the gas circulation system 208 may beused to reduce an amount of the one or more precursor materials that areused in the ALD process. The gas circulation system 208 may lowerprecursor waste by providing a circulation line 216 that may be coupledbetween the gas circulation system 208 and the input line 206. Thecirculation line 216 may be configured to transport the gas exiting thedeposition chamber 204 to the input line 206, which may cause the gasexiting the deposition chamber 204 to be transported back into thedeposition chamber 204 through the input line 206.

The gas circulation system 208 may also include a gas compositiondetection system 212. The gas composition detection system 212 may beconfigured to monitor the gas exiting the deposition chamber 204 and toproduce an output signal indicating a composition of the gas. The gascomposition detection system 212 may be coupled to a controller 218 viaa connection 214 (e.g., electrical connection, optical connection,etc.). The controller 218 may also be coupled to the gas supply 202 andmay control the providing of the one or more precursor materials by thegas supply 202 to the deposition chamber 204. The controller 218 maycontrol the providing of the one or more precursor materials based onthe output signal of the gas composition detection system 212.

The gas circulation system 208 may further include a filter 230, wherethe filter 230 is configured to remove contaminants or particles fromthe gas exiting the deposition chamber 204. The removal of thecontaminants or particles from the gas exiting the deposition chamber204 by the filter 230 may occur prior to the transporting of the gasback into the deposition chamber 204 via the circulation line 216. Thecontaminants or particles removed by the filter 230 may be stored in thefilter 230 or may be exhausted or otherwise discarded via a line 238 ofthe filter 230.

In some situations, it may be determined that the filter 230 is notnecessary (e.g., the gas exiting the deposition chamber 204 isrelatively particle-free). This determination may be made, for example,based on a signal produced by the gas composition detection system 212.The signal that may determine whether the filter 230 is necessary orunnecessary may be the output signal indicating the composition of thegas that is provided to the controller 218, or the signal may be adifferent signal generated by the gas composition detection system 212.In another example, the determination of whether to use the filter 230may be a decision that is made manually by an operator of the system200, or the determination may be made using a different (e.g., external)system or component (not depicted in the example of FIG. 2).

When the filter 230 is not to be used in removing the contaminants orparticles from the gas exiting the deposition chamber 204, a bypass line222 may be used. The bypass line 222 may allow the gas exiting thedeposition chamber 204 to be transported back into the depositionchamber 204 (i.e., via the circulation line 216) without passing throughthe filter 230. The bypass line 222 may be enabled or disabled. When thebypass line 222 is enabled, the gas exiting the deposition chamber 204may not pass through the filter 230, and when the bypass line 222 isdisabled, the gas exiting the deposition chamber 204 may pass throughthe filter 230.

The bypass line 222 may be enabled and disabled by controlling valves234 and 236. For example, when the valve 234 on the bypass line 222 isopen, and the valve 236 is closed, the bypass line 222 may be enabled,such that the filter 230 is not used in circulating the gas back intothe chamber 204. By contrast, when the valve 234 on the bypass line 222is closed, and the valve 236 is open, the bypass line 222 may bedisabled, such that the filter 230 is used to remove the contaminants orparticles prior to circulating the gas back into the chamber 204. Inanother example, both of the valves 234 and 236 may be open, thuscausing some of the gas exiting the chamber 204 to be filtered and someof the gas exiting the chamber 204 to not be filtered.

The controlling of the valves 234 and 236 may be based on an outputsignal produced by the gas composition detection system 212. Forexample, the gas composition detection system 212 may determine that thegas exiting the deposition chamber 204 is relatively particle-free andmay produce an output signal that causes the valve 234 to be opened andthe valve 236 to be closed, thus enabling the bypass line 222 anddisabling use of the filter 230. Alternatively, the gas compositiondetection system 212 may determine that the gas exiting the depositionchamber 204 requires filtering and may produce an output signal thatcauses the valve 234 to be closed and the valve 236 to be opened, thusdisabling the bypass line 222 and enabling use of the filter 230.

The example system 200 of FIG. 2 may further include a purge gasdelivery system 232 that is coupled to the deposition chamber 204. Thepurge gas delivery system 232 may be used to deliver a purge gas to thedeposition chamber 204 via one or more purge lines 248. The purge gasdelivery system 232 may include a gaseous tank or other facility thatprovides a purge gas such as argon, nitrogen, xenon, or anothernon-reactive gas to the deposition chamber 204. In one example, aplurality of purge lines 248 are used to deliver the purge gas to thedeposition chamber 204. Using the plurality of purge lines 248, asopposed to only a single purge line, a purging efficiency may beincreased in the example system 200.

The delivery of the purge gas from the purge gas delivery system 232 maybe used to maintain cleanliness in the deposition chamber 204 (e.g., toremove contaminants, particles, and other undesired matter from thedeposition chamber 204) and to control a flow of gases in the depositionchamber 204. The controlling of the flow of gases may be used, forexample, to remove precursor materials from the deposition chamber 204.For example, in an example ALD process where multiple precursormaterials are used, a first precursor material may be introduced in thechamber 204 for a first amount of time. The purge gas delivery system232 may be used to remove the first precursor material from the chamber204 prior to an introduction of a second precursor material to thechamber 204.

A vacuum pump 240 may also be included in the example system 200 toapply a pressure differential to the deposition chamber 204 to aid inthe removal of gases and other matter from the deposition chamber 204.Thus, the purge gas provided by the purge gas delivery system 232, alongwith the vacuum pump 240, may be used to purge precursor materials andother gases and matter from the deposition chamber 204. In one example,the purge gas delivery system 232 is controlled based on an outputsignal of the gas composition detection system 212. The output signal ofthe gas composition detection system 212 that controls the purge gasdelivery system 232 may be, for example, the output signal indicatingthe composition of the gas exiting the deposition chamber 204 via theoutput line 210.

FIG. 3 depicts an example deposition system 300 that may be used to forma deposited layer on a substrate or other structure. The deposited layermay be formed in the example system 300 of FIG. 3 using a depositionprocess such as atomic layer deposition (ALD). In the system 300, adeposition chamber 316 may receive precursor materials from a gas supply301 via a supply line 312. The gas supply 301 may be used to delivermultiple precursor materials to the deposition chamber 316 and thus maybe understood as including multiple different precursor deliverysystems. In the example of FIG. 3, three different precursor materialsmay be delivered to the deposition chamber 316 from the gas supply 301,and the gas supply 301 may be understood as including three differentprecursor delivery systems. The three different precursor deliverysystems may work in conjunction with one another to supply the variousdifferent precursor materials to the deposition chamber 316.

As illustrated in FIG. 3, each precursor delivery system may include aprecursor material supplier 302, which may be a gas storage tank,canister, or a machine used to generate the precursor material on anas-needed basis (e.g., in one example where ozone is utilized as aprecursor material, the precursor material supplier 302 may include aconcentrator or other ozone generator that can generate ozone asneeded). Each precursor delivery system may further include a pneumaticvalve 304 and a flow controller 306. The flow controller 306 may beutilized to control the flow of the precursor material to the depositionchamber 316 and may thereby help to control the pressure within thechamber 316. The flow controller 306 may be, for example, a proportionalvalve, a modulating valve, a needle valve, a pressure regulator, a massflow controller, combinations of these, or the like.

In other examples, each precursor delivery system may further include acarrier gas supply, where the carrier gas supply may supply a gas thatmay be used to help carry the precursor gas to the deposition chamber316. The carrier gas may be an inert gas or other gas that does notreact with the precursor material or other materials within thedeposition chamber 316. For example, the carrier gas may be helium (He),argon (Ar), nitrogen (N₂), hydrogen (H₂), combinations of these, or thelike. In examples where the carrier gas supply is used, the carrier gasmay enter the precursor material supplier 302 (e.g., the precursorcanister) and carry the gaseous precursor material towards thedeposition chamber 316.

The precursor delivery systems included in the gas supply 301 may beconnected to a precursor gas controller 308. The precursor deliverysystems may, using the precursor material suppliers 302, the pneumaticvalves 304, and the flow controllers 306, supply their individualprecursor materials to the precursor gas controller 308. The precursorgas controller 308 may connect and isolate the different precursordelivery systems from the deposition chamber 316 in order to allowdelivery of a desired precursor material to the deposition chamber 316.The precursor gas controller 308 may include such devices as valves,flow meters, sensors, and the like to control the delivery rates of eachof the precursors. As illustrated in FIG. 3, the precursor gascontroller 308 may be coupled to a controller 340, and the precursor gascontroller 308 may be controlled by instructions received from thecontroller 340. The gas supply 301 may also be coupled to the controller340, and the controller 340 may control the providing of the precursormaterials by the gas supply 301 by controlling the flow controllers 306or other components of the gas supply 301.

The precursor gas controller 308, upon receiving instructions from thecontroller 340, may open and close valves so as to connect one of theprecursor delivery systems to the deposition chamber 316 and direct adesired precursor material to the chamber 316 via the supply line 312.The supply line 312 may be coupled to an input line 314 of thedeposition chamber 316, such that the deposition chamber 316 receivesthe desired precursor material via the input line 314. The depositionchamber 316 may expose the precursor materials to a substrate placed onmounting hardware 318 included in the deposition chamber 316. Thedeposition chamber 316 may be any desired shape that may be suitable fordispersing the precursor materials and contacting the precursormaterials with the substrate. In one example, the deposition chamber 316may have a cylindrical sidewall and a bottom and may be surrounded by ahousing made of material that is inert to the various precursormaterials (e.g., steel, stainless steel, nickel, aluminum, alloys ofthese, or other combinations of these).

The deposition chamber 316 may have an output line 320 to allow theprecursor materials and other gases and matter to exit the depositionchamber 316. A vacuum pump 344 may be connected to the output line 320of the deposition chamber 316 in order to help evacuate the precursormaterials and the gases and other matter from the chamber 316. Thevacuum pump 344 may be under control of the controller 340 and may beutilized to reduce and control the pressure within the depositionchamber 316 to a desired pressure. A main valve 342 may be opened andclosed as needed to allow the vacuum pump 344 to apply a pressuredifferential to the deposition chamber 316.

The evacuation of the precursor materials and the other gases and matterfrom the deposition chamber 316 may also be aided by a purge gasdelivery system 339. The purge gas delivery system 339 may deliver apurge gas to the deposition chamber 316. The purge gas delivery system339 may include a gas canister 335 or other component that can provide apurge gas such as argon (Ar), nitrogen (N₂), or another non-reactive gasto the deposition chamber 316. The purge gas delivery system may furtherinclude a pneumatic valve 336 and a flow controller 338 (e.g., a massflow controller or another type of controller) and may be controlled bythe controller 340. The purge gas delivery system 339 may deliver thepurge gas to the deposition chamber 316 via a plurality of purge lines.By operating the plurality of purge lines simultaneously (e.g., inparallel), a purge efficiency of the purge gas delivery system 339 maybe increased.

A gas circulation system may be coupled to the output line 320 of thedeposition chamber 316, where the gas circulation system may be used toreduce an amount of precursor materials that are used in the depositionprocess. The gas circulation system may lower precursor waste byproviding a circulation line 328 that may be coupled between the outputline 320 and the input line 314 of the deposition chamber 316. Thecirculation line 328 may be configured to transport gas exiting thedeposition chamber 316 to the input line 314, which may cause the gasexiting the deposition chamber 316 to be transported back into thedeposition chamber 316 through the input line 314.

The circulation line 328 may include a circulation valve 330, where thecirculation valve 330 may be configured to open and close thecirculation line 328. When the circulation line 328 is opened by openingthe circulation valve 330, the gas exiting the deposition chamber 316may be transported back into the deposition chamber 316. When thecirculation line 328 is closed by closing the circulation valve 330, thegas exiting the deposition chamber may not be transported back into thedeposition chamber 316. When the circulation line 328 is closed in thismanner, the gas exiting the chamber 316 may be evacuated out of thesystem 300 and transported to an exhaust system by way of the vacuumpump 344 or otherwise forced to exit the system 300 without beingre-circulated through the chamber 316.

As noted above, the supply line 312 may be coupled to the input line 314of the deposition chamber 316, such that the deposition chamber 316 mayreceive precursor materials via the input line 314. As depicted in FIG.3, the supply line 312 may include a supply valve 310, where the supplyvalve 310 may be used to open and close the supply line 312. Thecirculation valve 330 and the supply valve 310 may be opened and closedto control a composition of a gas entering the deposition chamber 316through the input line 314.

In one example, the opening and closing of the circulation valve 330 andthe supply valve 310 may control i) an amount of the gas exiting thedeposition chamber 316, and ii) an amount of the precursor materialsfrom the gas supply 301 that are present in the gas entering thedeposition chamber 316 through the input line 314. Thus, the circulationvalve 330 and the supply valve 310 may be opened and closed to control amixture of gases entering the deposition chamber 316 through the inputline 314, where the mixture may include only the precursor materialsfrom the gas supply 301, only the gas exiting the deposition chamber 316via the output line 320, or a combination of the precursor materialsfrom the gas supply 301 and the gas exiting the deposition chamber 316via the output line 320.

The gas circulation system may also include a gas composition detectionsystem 346. The gas composition detection system 346 may be configuredto monitor the gas exiting the deposition chamber 316 and to produce anoutput signal indicating a composition of the gas. The output signal ofthe gas composition detection system 346 may be used to determine whengas exiting the deposition chamber 316 should be circulated back intothe chamber 316 via the circulation line 328 and when the depositionchamber 316 should be purged via the purge gas delivery system 339. Thegas composition detection system 346 may include one or more differentmonitoring components, including, for example, a Fourier transforminfrared spectroscopy (FTIR) system, a nondispersive infrared sensor(NDIR) system, or a Piezocon gas concentration sensor (PZC) system.Various other types of gas composition monitoring systems may be used inthe gas composition detection system 346.

The gas composition detection system 346 may be coupled to thecontroller 340 via a connection 332 (e.g., electrical connection,optical connection, etc.). As described above, the controller 340 mayalso be coupled to the gas supply 301 and the precursor gas controller308. The controller 340 may control the providing of the precursormaterials to the deposition chamber 316 by controlling the gas supply301 or the precursor gas controller 308. The controller 340 may controlthe gas supply 301 or the precursor gas controller 308 based on theoutput signal from the gas composition detection system 346. Further, inanother example, the circulation valve 330 and the supply valve 310 maybe opened and closed based on the output signal from the gas compositiondetection system 346 (e.g., to control a mixture of gases entering thechamber 316 via the input line 314, where the mixture may include gasesfrom the gas supply 301 and the gas exiting the chamber 316 via theoutput line 320).

The gas circulation system may further include a filter 326, where thefilter 326 is configured to remove contaminants or particles from thegas exiting the deposition chamber 316. The removal of the contaminantsor particles by the filter 326 may occur prior to the transporting ofthe gas back into the deposition chamber 316 via the circulation line328. The contaminants or particles removed by the filter 326 may bestored in the filter 326 or may be exhausted or otherwise discarded viaa line 350 of the filter 326.

If the filter 326 is determined to be unnecessary (e.g., where thedetermination may be made, for example, based on a signal produced bythe gas composition detection system 346), a bypass line 322 may beused. The bypass line 322 may allow the gas exiting the depositionchamber 316 to be transported back into the deposition chamber 316(i.e., via the circulation line 328) without passing through the filter326. The bypass line 322 may be enabled or disabled by controllingvalves 324 and 334. For example, when the valve 334 on the bypass line322 is open, and the valve 324 is closed, the bypass line 322 may beenabled, such that the filter 326 is not used in circulating the gasback into the chamber 316. By contrast, when the valve 334 on the bypassline 322 is closed, and the valve 324 is open, the bypass line 322 maybe disabled, such that the filter 326 is used to remove the contaminantsor particles prior to circulating the gas back into the chamber 316. Thecontrolling of the valves 324 and 334 may be based on an output signalproduced by the gas composition detection system 346. The valves 324 and334 may be, for example, pneumatic valves or other types of valves.

FIG. 4 is a flowchart 400 illustrating an example method for supplying aprecursor material for an atomic layer deposition (ALD) process. At 402,one or more precursor materials are provided to a deposition chamber. At404, a composition of a gas exiting the deposition chamber is monitored.At 406, the gas exiting the deposition chamber is transported back intothe deposition chamber via a circulation system. At 408, the providingof the one or more precursor materials and the transporting of the gasback into the deposition chamber are controlled based on the monitoredcomposition of the gas exiting the deposition chamber.

This written description uses examples to disclose the disclosure,including the best mode, and also to enable a person skilled in the artto make and use the disclosure. The patentable scope of the disclosuremay include other examples. It should be understood that as used in thedescription herein and throughout the claims that follow, the meaning of“a,” “an,” and “the” includes plural reference unless the contextclearly dictates otherwise. Also, as used in the description herein andthroughout the claims that follow, the meaning of “in” includes “in” and“on” unless the context clearly dictates otherwise. Further, as used inthe description herein and throughout the claims that follow, themeaning of “each” does not require “each and every” unless the contextclearly dictates otherwise. Finally, as used in the description hereinand throughout the claims that follow, the meanings of “and” and “or”include both the conjunctive and disjunctive and may be usedinterchangeably unless the context expressly dictates otherwise; thephrase “exclusive of” may be used to indicate situations where only thedisjunctive meaning may apply.

It is claimed:
 1. A method for supplying a precursor material for anatomic layer deposition (ALD) process, the method comprising: providinga precursor material from a gas supply to a deposition chamber via aninput line of the deposition chamber; producing an output signal, usinga gas composition detection system of a gas circulation system coupledto an output line of the deposition chamber, indicating a composition ofan exhaust gas exiting the deposition chamber through the output line,removing contaminants or particles from the exhaust gas, using a filter,prior to transporting of the exhaust gas back into the depositionchamber; allowing, using a bypass line, the exhaust gas to betransported back into the deposition chamber without passing through thefilter; causing, via a circulation line coupled to the bypass line, theexhaust gas to be mixed with the precursor material and transported backinto the deposition chamber; and controlling, using a controller coupledto the gas supply, (i) an amount of the precursor material beingprovided by the gas supply to the deposition chamber and (ii) an amountof the exhaust gas being transported by the gas circulation system backinto the deposition chamber, based on the output signal, duringdeposition, wherein the controller is configured to close a first valveand open a second valve to cause the exhaust gas to flow through thefilter based on the output signal of the gas composition detectionsystem indicating filtering is not necessary, and to open the firstvalve and close the second valve to cause the exhaust gas to bypass thefilter based on the output signal of the gas composition detectionsystem indicating filtering is necessary: such that, while a mixture ofthe precursor material and a downstream portion of the exhaust gas isflowing into the deposition chamber, an upstream portion of the exhaustgas is being monitored by the gas composition detection system beforebeing mixed with the precursor material.
 2. The method of claim 1,wherein the bypass line is configured to be enabled and disabled,wherein the exhaust gas does not pass through the filter when the bypassline is enabled, and wherein the exhaust gas passes through the filterwhen the bypass line is disabled.
 3. The method of claim 1, wherein thebypass line is enabled and disabled by controlling the first valve, andwherein the enabling and disabling of the bypass line is based on theoutput signal of the gas composition detection system, and wherein thesystem includes the first valve configured to control gas flow throughthe bypass line and the second valve configured to control gas flow tothe filter.
 4. The method of claim 1, further comprising opening andclosing the circulation line using a circulation valve of the gascirculation system; wherein when the circulation line is opened by thecirculation valve, the exhaust gas is transported back into thedeposition chamber, and wherein when the circulation line is closed bythe circulation valve, the exhaust gas is not transported back into thedeposition chamber.
 5. The method of claim 4, further comprising:transporting, via a supply line coupled to the gas supply and to theinput line, the precursor material from the gas supply to the inputline, wherein the supply line includes a supply valve, the supply valveis configured to open and close the supply line.
 6. The method of claim5, wherein the circulation valve and the supply valve are opened andclosed to control a composition of a gas entering the deposition chamberthrough the input line, and wherein the circulation valve and the supplyvalve are opened and closed based on the output signal of the gascomposition detection system.
 7. The method of claim 1, furthercomprising: delivering, using a purge gas delivery system, a purge gasto the deposition chamber via one or more purge lines.
 8. The method ofclaim 7, wherein the purge gas delivery system is controlled based onthe output signal of the gas composition detection system.
 9. The methodof claim 7, further comprising controlling, using the purge gas deliverysystem, a flow of gases in the deposition chamber.
 10. The method ofclaim 7, further comprising delivering the purge gas to the depositionchamber via a plurality of purge lines.
 11. The method of claim 10,wherein the plurality of purge lines are operated simultaneously. 12.The method of claim 1, wherein the gas composition detection systemincludes a Fourier transform infrared spectroscopy (FTIR) system, anondispersive infrared sensor (NDIR) system, or a Piezocon gasconcentration sensor (PZC) system.
 13. The method of claim 1, furthercomprising controlling, using the controller, which of the plurality ofgas sources is provided to the deposition chamber wherein the gas supplyincludes a plurality of gas sources.
 14. The method of claim 1, furthercomprising: controlling flow, using a circulation valve, of the exhaustgas to the deposition chamber's input line; and controlling, using asupply valve, flow of supply gas to combine with the exhaust gas thathas exited the circulation valve and is in the deposition chamber'sinput line.
 15. The method of claim 1, further comprising: controlling,using a precursor delivery system comprising a pneumatic valve and aflow controller, the flow of the precursor material to the depositionchamber.
 16. A method for supplying a precursor material for an atomiclayer deposition (ALD) process, the method system comprising: providing,via a gas supply, one or more precursor materials to a depositionchamber; transporting, via a gas circulation system coupled to an outputline of the deposition, exhaust gas exiting the deposition chamber to aninput line of the deposition chamber; reducing, using a filter coupledto the gas circulation system, contaminants in the gas being transportedback into the deposition chamber; controlling, using a first valve, flowthrough the bypass line; controlling, using a second valve, flow to thefilter by closing the first valve and opening the second valve to causethe exhaust gas to flow through the filter; producing, using a gascomposition detection system coupled to the output line, an outputsignal indicating a composition of the exhaust gas exiting thedeposition chamber; controlling, during deposition using a controllercoupled to the gas supply, (i) an amount of the one or more precursormaterials being provided to the deposition chamber and (ii) and amountof the exhaust gas being transported back to the deposition chamber,based on the output signal of the gas composition detection system,wherein the controller is configured to close the first valve and openthe second valve to cause the exhaust gas to flow through the filterbased on the output signal of the gas composition detection systemindicating filtering is not necessary, and to open the first valve andclose the second valve to cause the exhaust gas to bypass the filterbased on the output signal of the gas composition detection systemindicating filtering is necessary.
 17. A method for supplying aprecursor material for an atomic layer deposition (ALD) process, themethod comprising: providing one or more precursor materials to adeposition chamber; monitoring a composition of a gas exiting thedeposition chamber; transporting the gas exiting the deposition chamberback into the deposition chamber via a circulation system; andcontrolling i) the providing of the one or more precursor materials, andii) the transporting of the gas back into the deposition chamber basedon the monitored composition of the gas exiting the deposition chamber.18. The method of claim 17, further comprising: delivering a purge gasto the deposition chamber via a plurality of purge lines, wherein thedelivering is controlled based on the monitored composition of the gasexiting the deposition chamber.
 19. The method of claim 17, furthercomprising: producing an output signal, using a gas compositiondetection system of the circulation system coupled to an output line ofthe deposition chamber, indicating a composition of an exhaust gasexiting the deposition chamber through the output line.
 20. The methodof claim 17, wherein the controller is configured to close a first valveand open a second valve to cause the gas exiting the deposition chamberto flow through a filter based on an output signal of a gas compositiondetection system indicating filtering is not necessary, and to open thefirst valve and close the second valve to cause the gas exiting thedeposition chamber to bypass the filter based on the output signal ofthe gas composition detection system indicating filtering is necessary:such that, while a mixture of the one or more precursor materials and adownstream portion of the gas exiting the deposition chamber is flowinginto the deposition chamber, an upstream portion of the gas exiting thedeposition chamber is being monitored by the gas composition detectionsystem before being mixed with the one or more precursor materials.